Add a second SSD, if the motherboard has a SATA port (I assume your current one is an NVMe drive). A SATA SSD is still more than fast enough as a second drive.
Moving to a bigger SSD also isn’t too difficult, as long as you have a system where you can have both the old and new SSD connected at the same time. It can be a different system if needed. Download Clonezilla onto a USB stick with Ventoy on it, and boot into it. Just make sure you have backups and do the clone in the correct direction (don’t clone the blank new drive onto the old one!!)
This seems like overkill compared to just running it on a VPS and having a second VPS as a hot spare.